Gunman kills member of Afghan peace council

An Afghan National Army soldier patrols the gate of the military hospital next to an ambulance in Kabul, Afghanistan, Sunday, May 13, 2012. 2012. Arsala Rahmani, a former Taliban official turned Afghan peace negotiator, was in his vehicle when he was killed by an unknown attacker in another vehicle in western Kabul earlier Sunday. (AP Photo/Rahmat Gul)
— AP

An Afghan National Army soldier patrols the gate of the military hospital next to an ambulance in Kabul, Afghanistan, Sunday, May 13, 2012. 2012. Arsala Rahmani, a former Taliban official turned Afghan peace negotiator, was in his vehicle when he was killed by an unknown attacker in another vehicle in western Kabul earlier Sunday. (AP Photo/Rahmat Gul)
/ AP

Ashraf Ghani, who is head of a commission overseeing the transition to Afghan-led security, gestures while announcing a list of areas where Afghan forces will take the lead from foreign troops during a press conference in Kabul, Afghanistan, Sunday, May 13, 2012. The Afghan government says it is taking the lead from the U.S.-led coalition for providing security in areas that will eventually make up 75 percent of the country's population. (AP Photo/Rahmat Gul)— AP

Ashraf Ghani, who is head of a commission overseeing the transition to Afghan-led security, gestures while announcing a list of areas where Afghan forces will take the lead from foreign troops during a press conference in Kabul, Afghanistan, Sunday, May 13, 2012. The Afghan government says it is taking the lead from the U.S.-led coalition for providing security in areas that will eventually make up 75 percent of the country's population. (AP Photo/Rahmat Gul)
/ AP

Ashraf Ghani, who is head of a commission overseeing the transition to Afghan-led security, gestures while announcing a list of areas where Afghan forces will take the lead from foreign troops during a press conference in Kabul, Afghanistan, Sunday, May 13, 2012. The Afghan government says it is taking the lead from the U.S.-led coalition for providing security in areas that will eventually make up 75 percent of the country's population. (AP Photo/Rahmat Gul)— AP

Ashraf Ghani, who is head of a commission overseeing the transition to Afghan-led security, gestures while announcing a list of areas where Afghan forces will take the lead from foreign troops during a press conference in Kabul, Afghanistan, Sunday, May 13, 2012. The Afghan government says it is taking the lead from the U.S.-led coalition for providing security in areas that will eventually make up 75 percent of the country's population. (AP Photo/Rahmat Gul)
/ AP

Afghan National Army soldiers secure the gate of the military hospital after Arsala Rahmani, a former Taliban official turned Afghan peace negotiator, was killed by an unknown attacker in western Kabul, Sunday, May 13, 2012. (AP Photo/Rahmat Gul)— AP

Afghan National Army soldiers secure the gate of the military hospital after Arsala Rahmani, a former Taliban official turned Afghan peace negotiator, was killed by an unknown attacker in western Kabul, Sunday, May 13, 2012. (AP Photo/Rahmat Gul)
/ AP

KABUL, Afghanistan 
A gunman in a car assassinated a former high-ranking Taliban official working to end the decade-long war in Afghanistan, dealing a powerful blow Sunday to the fragile, U.S.-backed effort to bring peace to the country.

Arsala Rahmani, a top member of the Afghan peace council and a senator in Parliament, was killed a week before a key NATO summit and just hours before President Hamid Karzai announced the third stage of a five-part transition that is supposed to put Afghan security forces in control of their country by the end of 2014.

Police said an assassin with a silencer-equipped pistol shot Rahmani, who was in his 70s, as he was riding in his car in one of the capital's most secure areas, near Kabul University. The gunman fired from a white Toyota Corolla that pulled up alongside Rahmani's vehicle at an intersection. Rahmani's driver rushed him to a hospital, but he died on the way, police said.

Rahmani was a former deputy minister of higher education in the Taliban regime that was ousted by the U.S.-led invasion in 2001. He eventually reconciled with the government and was trying to set up formal talks with the insurgents.

The killing was another setback to efforts to negotiate a political resolution to the war. In September 2011, former Afghan President Burhanuddin Rabbani, who was head of the peace council, was assassinated in his Kabul home by a suicide bomber posing as a peace emissary from the Taliban.

The Taliban denied responsibility for Rahmani's killing, although they had publicly threatened to target peace negotiators and others working with the government.

Agha Jan Motasim, a member of the Taliban leadership council known as the Quetta Shura, condemned Rahmani's assassination.

"He was a good Muslim. He was a nationalist and worked for an Islamic system in Afghanistan. We respected him," Motasim said from Turkey, where he is recovering from gunshot wounds suffered last year in Pakistan.

The U.S.-led coalition is trying to wind down its involvement in Afghanistan by finding a political resolution to the war and training Afghan security forces to take the lead in protecting their homeland. But a recent rise in violence has raised concerns about the Afghan government's readiness to assume responsibility for the country's security. If the government fails, the Taliban could stage a comeback.

The third and latest phase in the transition to Afghan-led security was announced with fanfare by Afghan officials.

Ashraf Ghani, head of a commission overseeing the transition, said that this stage - which ends with the Afghans taking the lead in areas representing 75 percent of the population of some 34 million - should be complete within six months.

"The third transition will be difficult - we don't want to lie to the Afghan people," Ghani acknowledged last week. But he added that the nation is strongly determined to take control of its own affairs.

Karzai's announcement means that Afghan forces already, or soon will, lead security in all 34 provincial capitals and 260 of Afghanistan's more than 360 districts. When the third phase of transition is complete, nearly a dozen provinces in their entirety will be under Afghan control.